The present invention relates to an improved process for preparing a broad variety of phenyl esters of the general formula (I): EQU R--ACH(R.sub.1)CO.sub.2 Ph(CH.sub.2).sub.n --R.sub.2 (I)
More particularly, the present invention relates to an improved two-step process for preparing phenyl esters of substituted acetic acids of formula (I), i.e., where R.sub.1 is H.
The present invention also includes the discovery of novel phenyl ester intermediates of such process which can be identified by the general formula EQU XCH(R.sub.1)CO.sub.2 Ph(CH.sub.2).sub.n --R.sub.2 (II)
as well as methods for the utilization of these intermediates as alkylating agents for amides, amines, carboxylic acids, mercaptans and phosphines.
The term "bleach activator" is understood in the art to describe a relatively stable compound which decomposes in water in the presence of a peroxygen to produce the corresponding peracid bleaching agent. The subject phenyl esters of formula (I) are useful as bleach activators or as precursors to bleach activators.
U.S. Pat. No. 4,681,592 discloses, inter alia, bleach activators of the formula: ##STR1## wherein R is hydrocarbyl or alkoxylated hydrocarbyl; X is, inter alia, SO.sub.2, N(R').sub.2 or P(R').sub.2 ; and R' is H or alkyl.
European Patent Application No. 284,292 discloses, inter alia, peracid precursors of formula: ##STR2## and R.sub.1, R.sub.2 and R.sub.3 are, inter alia, C.sub.1 -C.sub.30 alkyl.
U.S. Pat. No. 4,634,551 discloses, inter alia, bleach activators of the formula: ##STR3## wherein R.sup.1 is an alkyl(ene), aryl(ene) or alkaryl(ene) group; and R.sup.5 is H or an alkyl, aryl or alkaryl group.
U.S. Pat. No. 4,778,618 discloses, inter alia, bleach activators of formula: ##STR4## wherein R is C.sub.1 -C.sub.20 linear or branched chain alkyl, alkylethoxylated, cycloalkyl, aryl, substituted aryl; R' and R" are independently H, C.sub.1 -C.sub.20 alkyl, aryl, C.sub.1 -C.sub.20 alkylaryl, substituted aryl, and NR.sub.3.sup.a +; and R.sup.a is C.sub.1 -C.sub.30 alkyl.
The subject phenyl esters are conventionally prepared from the corresponding substituted acetic acids using methods which are known in the art. In most cases the substituted acetic acid can be converted to the corresponding acid chloride which is then reacted with an appropriately substituted phenol in the presence of a base or with a preformed salt of the phenol.
Known processes require three or more steps to prepare a phenyl ester of formula (I); they proceed via a substituted acetic acid; and they require the preparation of at least one acid chloride.
U.S. Pat. No. 3,130,165 discloses phenyl esters of lower (C.sub.2 -C.sub.3) alpha-chlorocarboxylic acids as bleach activators. Among the preferred esters is chloroacetyl phenol-4-potassium sulfonate of the formula: ##STR5## U.S. Pat. No. 3,130,165 does not disclose a method for preparing this compound.
U.S. Pat. No. 4,483,778 discloses, inter alia, bleach activators derived from higher (C.sub.6 -C.sub.16) alpha-chlorocarboxylic acids of the formula ##STR6## wherein R is a straight or branched alkyl or alkenyl group having from about 4 to about 14 carbon atoms, R.sup.1 is H, CH.sub.3, C.sub.2 H.sub.5 or C.sub.3 H.sub.7, and L is, inter alia, phenol sulfonate.
U.S. Pat. No. 3,130,165 and U.S. Pat. No. 4,483,778 strongly suggest that phenyl esters of formula (II) are subject to nucleophilic attack at the ester carbonyl with concomitant cleavage of the phenyl ester. (The term nucleophile is generally understood in the art to describe any reagent that brings an electron pair. The reaction of a nucleophile is termed as nucleophilic.) It has now been discovered that under certain conditions phenyl esters of formula (II) react with nucleophiles to give products resulting from displacement of the halide group X with preservation of the phenyl ester.
In addition, it has been discovered that phenyl esters of formula (II) can be simply and efficiently prepared from alpha-haloacetyl halides under a variety of conditions.
It has further been discovered that the novel compound 4-(chloroacetyloxy)benzene sulfonic acid, sodium salt, is a particularly useful intermediate for the preparation of bleach activators derived from substituted acetic acids.